A DENDROMETRIC MODEL FOR ESTIMATION OF THE DIAMETER AT BREAST HEIGHT FROM STUMP DIMENSIONSOriginal Title (non-English) UN MODELO DENDROMETRICO PARA ESTIMACION DEL DIAMETRO NORMAL A PARTIR DE LAS DIMENSIONES DEL TOCON [Spanish]

摘要

After cuttings have been carried out in forest stands, the estimation of normal diameter (D) in function of the stump dimensions is important for the characterization of the original stand structure and the definition of management guidelines. Its estimation is based on a linear relationship with the stump diameter, which is always assumed to occur at a same height. The objective of this study was to propose a dendrometric nonlinear model which includes stump height as a predictive variable. Data were adjusted from 304 Pinus durangesis trees felled and used in the area of influence of Silvicultores Unidos de Guachochi, in the southwestern part of the Chihuahua State during 2009. Its goodness of fit was tested through bias, root mean square error and the adjusted coefficient of determination, and yield values of 2.39, 5.74 and 0.96. These criteria indicate that the model estimated satisfactorily the diameter at breast height over bark. Inclusion of stump height improved the accuracy of the model and is consistent to predict diameter of different sizes. Due to the fact that in the region there are total volume equations, it is recommended to use the model to predict the normal diameter and then apply local volume equations to estimate the volume of the log.